Countercurrent-preventing protection and control method for microgrid

Abstract

The invention relates to a countercurrent-preventing protection and control method for a microgrid. The method comprises the following steps that (1) when Ps-P1>Pa, the method turns to a step (2); when P1-Ps>Pb, the method turns to a step (3); when -Pb<=Ps-P1<=Pa, the current state of the microgrid is kept unchanged; (2) the current capacity of an energy storage system is detected, and if the current capacity of the energy storage system does not reach the upper energy limit of the energy storage system, the method turns to a step (4); if the current capacity of the energy storage system reaches the upper energy limit of the energy storage system, the method turns to a step (5); (3) the microgrid is switched to be in a grid-connection mode, and the load gap of the microgrid is supplemented through a public supply network and the energy storage system; (4) the microgrid is switched to be in an island mode, and the energy storage system absorbs redundant distributed power generation capacity in a charging mode; (5) the microgrid is switched to be in the island mode, a controllable switch on a line connected between an additional load and an alternating current bus is powered off, and redundant power sent by the microgrid is absorbed through the additional load.

Description

technical field [0001] The invention relates to an anti-backflow protection control method for a microgrid, belonging to the field of distributed power generation. Background technique [0002] At present, energy conservation and emission reduction and green energy have become the focus of attention all over the world, and they are also one of the goals of my country's smart grid construction. As a smart grid, it is required that it can not only adapt to the access of large power sources, but also support the friendly access of renewable energy in the form of distributed power generation, so as to meet the requirements of harmonious development of electricity, the natural environment, and social economy. [0003] However, distributed power sources such as photovoltaics have the characteristics of intermittent, random, slow response, and small inertia. After grid connection, they are prone to voltage fluctuations and flicker, especially when large-capacity distributed power s...

AI Technical Summary

Problems solved by technology

However, this technology mainly eliminates reverse power by limiting the output of distributed power sources or even cutting off distributed power sources. This is neither in line with the national policy of requiring surplus power to be connected to the grid, nor is it conducive to the normal operation of distributed power sources. At the same time, it is not fully utilized. New energy, causing waste of renewable energy

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